OMIA:001916-9796 : Familial adenomatous polyposis in Equus caballus (domestic horse) |
Categories: Skeleton phene (incl. short stature & teeth) , Neoplasm
Links to possible relevant human trait(s) and/or gene(s) in OMIM: 175100 (trait) , 611731 (gene)
Links to relevant human diseases in MONDO:
Single-gene trait/disorder: yes
Mode of inheritance: Probably autosomal dominant
Disease-related: yes
Key variant known: yes
Year key variant first reported: 2026
Cross-species summary: In humans, the disease is also called Gardner Syndrome.
Molecular basis: Martin et al. (2026): "Whole genome sequencing and variant discovery in the [affected] pony identified multiple unique variants, including a likely pathogenic single base pair insertion leading to a frameshift in APC (ENSECAP00000007276.1:p.Glu1527ArgfsTer9) [omia.variant:1897]."
Clinical features: Martin et al. (2026) report a 12 year-old-pony mare with "bilateral nasal discharge, cutaneous masses, and numerous hard enlargements involving the bones of the skull, maxilla, mandible, and cervical vertebrae. Oral exam revealed advanced dental disease with hard enlargements adjacent to and between numerous cheek teeth. Radiographs and computed tomography confirmed the presence of severe dental disease and proliferative bone lesions disseminated along the skull, hyoid apparatus, and cranial cervical vertebrae. The bony proliferations extended into the subcutis, nasal cavity, paranasal sinuses, orbits, cranial vault, and vertebral canal."
Pathology: Martin et al. (2026): "On necropsy, multiple osteomas were present on the skull and to a lesser extent the cervical vertebrae. Additional abnormalities included multiple mucosal polyps in the small intestine, epidermal inclusion cysts, and adrenocortical adenomas."
Breed:
Pony (Horse) (VBO_0001052).
Breeds in which the phene or likely causal variants have been documented. If a likely causal variant has been documented, see variant-specific breed information in the variant table. (Breed information may be incomplete).
Associated gene:
| Symbol | Description | Species | Chr | Location | OMIA gene details page | Other Links |
|---|---|---|---|---|---|---|
| APC | APC regulator of WNT signaling pathway | Equus caballus | 14 | NC_091697.1 (75042476..74925880) | APC | Ensembl, NCBI gene |
Variants
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WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.
Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.
| OMIA Variant ID | Breed(s) | Variant Phenotype | Gene | Allele | Variant Type | Variant Effect | Source of Genetic Variant | AVCG Pathogenicity Classification* | Reference Sequence | Chr. | g. or m. | c. or n. | p. | Verbal Description | EVA ID | Year Published | PubMed ID(s) | Acknowledgements |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1897 | Pony (Horse) | Familial adenomatous polyposis | APC | delins, small (<=20) | frameshift | Naturally occurring variant | Not currently evaluated | EquCab3.0 | 14 | NC_009157.3:g.58546516dup | NM_001301314.1:c.4656dup | NP_001288243.1:p.(E1553Rfs*9) | Published as g.58546511C>CT; p.(E1527Rfs*9); c.4578dup - coordinates in this table presented based on HGVS 3' rule and NCBI reference transcript. | 2026 | 42038751 |
* Variant pathogenicity for single-gene diseases as evaluated according to the Animal Variant Classification Guidelines (AVCG) by the Variant Pathogenicity Working Group of the International Society of Animal Genetics (ISAG) Animal Genetic Testing Standardization (AGTS) Standing Committee: P = pathogenic, LP = likely pathogenic, VUS = variant of unknown significance, LB = likely benign, B = benign. For more information (including details on the classification of each variant) see LINKS.
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Cite this entry
Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2026). OMIA:001916-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset]. https://omia.org/. https://doi.org/10.25910/2AMR-PV70
Reference
| 2026 | Martin, J.E., Hecht, S., Craig, L., Durward-Akhurst, S.A., Marlowe, J.L., Hines, M.T. : |
| Germline pathogenic variant in the APC gene suggestive of Gardner syndrome in a pony. Case Rep Vet Med 2026:1395580, 2026. Pubmed reference: 42038751. DOI: 10.1155/crve/1395580. |
Edit History
- Created by Imke Tammen2 on 30 Apr 2026
- Changed by Imke Tammen2 on 30 Apr 2026